This application is a request for funding to help purchase a Philips Techani 12 TEM/Stem electron microscope. The instrument will replace a Philips EM400 instrument, which is over 20 years old and is reaching the end of its useful life. It also lacks state of the art features of the new instruments, which are greatly needed for rapid collection of high-resolution data. The Technai 12 TEM/Stem will go into a well continuously for 22 years. The core facility has all of the required advisory groups, charge systems, and personnel for daily operation required for a shared instrument. This facility under the direction of Dr. Jack Griffith serves NIH funded investigators both at UNC and across the US in need of the visualization of their nucleic acid and nucleic acid-protein complexes. This facility and its operation is highly unique: in the past 10 years, 60 papers involving EM have been published in high profile journals resulting from our providing EM expertise to other NIH funded P.I.?s and this year (2000-2001) we are engaged in work with 33 NIH funded laboratories across the US. The Technai 12 TEM/Stem with grater resolution, new imaging modes, the ability to capture images directly to a computer, and the ability for this instrument to be used by our collaborators at their home institutions via a high speed internet connection are all essential to the continuation of this important local and national operation.